Since the house already exists and we don’t want to do any more building, what are the chances we could lose this property, occupancy could be denied, inability to resell etc. after we bought it?

All of them are from applicants who became upset when we denied their applications.. hehe I turned off Facebook reviews because of applicants who were also denied. 

Your experience doesn't seem too unusual - you will receive a large number of inquiries, your job (or the property managers job) is to sort them and provide quick and clear responses to applicants on next steps (denied and reason for denial, etc).

We got denied any loans because of our debt ratio, which I knew was high because I am on disability.

But if everyone denies it and the water bill goes up do to usage, then everyone will receive a rent increase. 

I'm very happy in my current career, but cannot deny the impact that real estate is having on my local Metro Area of Nashville, TN.

The other thing is the wholesaler is usually promising to the owner a quick sale so even if the property would adhere to a conventional lenders parameters, they may deny it because it would take too long to close.

Tenant has denied access to landlord and representatives who need access to the house (contractors to repair things and realtor to show the house to prospective buyers).

Add in the fact they can change rules, deny rentals, etc and it just isn't attractive.

And with that many adults, it may even be tricky and you could have trouble monitoring it 24/7 (and, of course, they will likely deny the unauthorized people live there).